In Python '\' is converted to '\\' even with rawstring or unicode settings

Question

I am relatively new to python and now have the following problem. Since recently whenever I generate or include a path in a code the \ is replaced by \. Like e.g. when using

os.join

or when using

r'mypat\myfiles\myfile.py'

or

u'mypat\myfiles\myfile.py'

A work around I found for myself so far was using '/' instead of '\' which did the job. But now I want to manually install a package and get the error

path wrong: C:\\Program Files\\Anaconda2\\pkgs\\...

I assume its something in the settings of either on my computer or the basic python settings. Its Window 7 and I tried German and English Language settings with the same result.

`print r'mypat\myfiles\myfile.py'` will output only 1 `'\'`. `'\\'` is internal string representation of `'\'`. — Mohammad Yusuf, Feb 02 '17 at 11:32

score 2 · Answer 1 · answered Feb 02 '17 at 10:53

2

You have to escape them with an additional slash:

print('mypat\\myfiles\\myfile.py')

answered Feb 02 '17 at 10:53

lapinkoira

8,320
9
51
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print(r'mypat\\myfiles\\myfile.py') generates mypat\\myfiles\\myfile.py – horseshoe Feb 02 '17 at 10:59
But why do you need to use the string representation, 'r' ? – lapinkoira Feb 02 '17 at 11:01
@lapinokira: because print(r'mypat\myfiles\myfile.py') also generates mypat\\myfiles\\myfile.py. – horseshoe Feb 02 '17 at 11:49

score 2 · Accepted Answer · edited May 23 '17 at 11:45

2

os.path.join() is multi-platform, if used on Windows, it will generate a windows path with \, for linux it will generate a linux path with "/

Linux :

Python 3.6.0 (default, Dec 24 2016, 08:03:08) 
[GCC 6.2.1 20160830] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.join("toto", "tutu")
'toto/tutu'
>>>

Windows :

λ python
Python 3.5.3 (v3.5.3:1880cb95a742, Jan 16 2017, 16:02:32) [MSC v.1900 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.join("toto", "tutu")
'toto\\tutu'
>>>

You should never use an hardcoded path in your code. If your software is multi-platform, write path using linux style and then build it using os.path.join, it will be reformated

An other post which could interest you : mixed slashes with os.path.join on windows

edited May 23 '17 at 11:45

Community

1
1

answered Feb 02 '17 at 10:54

PyNico

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5
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Thx. So If I want to use a code that uses os (and that I cannot change) on a windows machine, what can I do that its not toto\\tutu but toto\tutu? – horseshoe Feb 02 '17 at 11:04
toto\\tutu is valid, toto\tutu is not valid , toto/tutu is valid. I would always use "/". (not sure to understand). If you really want have "\". i would just build my path, then replace "\\" or "/" with "\" – PyNico Feb 02 '17 at 11:07
Thanks, I think the link and your comments made it clear to me. I thought the \\ was the problem that the code couldn't find the path but I guess I have to search elsewhere. – horseshoe Feb 02 '17 at 12:03

In Python '\' is converted to '\\' even with rawstring or unicode settings

2 Answers2